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Why it's so hard for Toyota to find out what's wrong with its vehicles

I won’t lie to you: I was not a good engineering student. That’s one of the reasons I went into journalism. But I did manage to acquire a bachelor of sciences in mechanical engineering, and the recent Toyota hearings on Capitol Hill brought back a lot of memories. Specifically, memories about how engineers figure out why mechanical things fail.

It was made painfully clear at the hearings that a number of lawmakers do not understand the process. An exchange between Rep. Eleanor Holmes Norton (D-D.C.) and Toyota president Akio Toyoda illustrated the problem.

Toyoda said that when his company gets a complaint about a mechanical problem, engineers try to duplicate the problem in their labs as a way of trying to find out what went wrong. Norton said: “Your answer — we’ll wait to see if this is duplicated — is very troublesome.”

Norton asked Toyoda why his company waited until a problem happens again to try to diagnose it, which is exactly what he was not saying.

Members of Congress are lawyers and politicians, not engineers. But they are launching investigations and creating policies that have direct impact on the designers and builders of incredibly complex vehicles — there are 20,000 parts in a modern car — so there are some basics they should understand. Chief among them: The only way you can credibly figure out why something fails is to attempt to duplicate the failure under observable conditions. This is the engineering method.

“It’s just so difficult for people to understand the complexity of the thing,” said David E. Cole, chairman of the Center for Automotive Research and an engineer. “They don’t have the background. They don’t have the time to do an investigation. They want to oversimplify a thing that can’t be oversimplified.”

Toyota is facing an incredibly difficult task. Here’s what it knows: It has received hundreds of complaints of unintended acceleration in its vehicles over the past several years. People have died in these crashes. Over the same period of time, hundreds more people have died in Toyota crashes that had nothing to do with runaway acceleration. After that, it knows nothing.

Toyota must search its data and look for patterns, for similarities among the incidents. It must consider the kinds of road conditions where they happened (Is it a rain/snow/sleet/temperature problem?), where the cars were made (Is it a parts or assembly problem?), how the cars were drawn up (Is it a design flaw? If so, is it a mechanical or electronic flaw? Or a combination?), how the cars were tested (Did we fail to anticipate a series of events that would lead to a flaw?), it if is a fatigue problem (Did something break down sooner than we thought it would?) and a dozen other variables I’m not thinking of.

Then you go through a process of elimination. It’s not dissimilar to a doctor diagnosing an illness: You take a thorough reading of the symptoms then start eliminating causes. You treat what you think is the illness. If it doesn’t go away, you treat your second guess at the illness.

Toyota appears from the start to have removed its electronic throttle control from the list of possible causes of the runaway acceleration and focused on two mechanical issues: floor-mat entrapment and sticky gas pedals.

But the National Highway Traffic Safety Administration is expanding its search for the problem. It purchased a 2006 Lexus that experienced runaway acceleration and will test it for everything it can think of — including electronic problems. I asked NHTSA about the Lexus testing, which will take place at the agency’s facility in East Liberty, Ohio, but no details were available yet.

So I called Prof. Giorgio Rizzoni of Ohio State University, an expert in failure analysis and director of the school’s Center for Automotive Research. I asked him: How will NHTSA test its Lexus?

First, he said, the vehicle will be outfitted with instruments and taken to a proving ground. There it will be driven for hours by a test-driver to see if the runaway acceleration can be duplicated.

“But what if you keep driving for days and days and the fault doesn’t come back,” Rizzoni said. “What do you do at that point?”

Then, the car is taken into a lab and taken apart.

If the electronic throttle control is the suspected culprit, it is removed from the Lexus and set up on a test bench, where it is affixed with monitoring equipment and a power source. You give it juice and see what happens; see if there are drops or surges in micro-voltage that could lead to runaway acceleration, for instance.

If that doesn’t provide the answer, you go 21st-century on the thing. You run something called a “hardware-in-the-loop simulation,” where you hook up the physical throttle assembly to a virtual Lexus, via a complex computer. This lets you test the throttle control up-close while it is subjected to road conditions, via the computer simulation. You can run tests for days on end without the expense of a test-driver.

Though attention has been focused on mechanical and electronic issues, Rizzoni raised another possible cause of the runaway acceleration: a software glitch.

He explained that each vehicle on the road today contains “layers of computer code that may be added from one model year to next” that control nearly every system of a vehicle, from acceleration to braking to stability. Rizzoni said this software is rigorously tested before it is put into vehicles, but added: “It is well-known in our community that there is no scientific, firm way of actually, completely verifying and validating software.”

Here’s an example everyone is familiar with: You’re working at your computer in Windows software and an error message pops up. It asks if you want to report the error to Microsoft. Microsoft has exhaustively tested this version of Windows before its release, but it cannot completely predict how it will operate in the wild, subject to user demands. That’s why it gathers error reports and uses them to fix the software on a rolling basis.

If you put a lot of parts together to form a complex electro-mechanical machine and make it talk to itself via software, it can behave, sometimes, in ways you cannot anticipate. It can fail for reasons you cannot anticipate.

That’s the problem Toyota faces. And. after thorough testing by Toyota, and NHTSA and garage mechanics trying to win the $1 million prize, no single answer may be found. Obviously, this will not stop juries from awarding damages in the liability lawsuits already filed.

Finally, Toyota can’t say this, but I can: Some of the cases of runaway acceleration could have been caused by driver error. Think about the times you’ve been in an accident, a near-miss or — more to the point — a distracted-driving situation that almost got out of control. You remember the white-hot spike of fear that shot up your spine. You remember the shakes afterward. But do you remember what you did during those few seconds of panic? Do you remember where your feet and hands and eyes went?

Quoting from a 2009 Los Angeles Times story on runaway Toyota acceleration:

Richard Schmidt, a former UCLA psychology professor and now an auto industry consultant specializing in human motor skills, said the problem almost always lies with drivers who step on the wrong pedal.

"When the driver says they have their foot on the brake, they are just plain wrong,’ Schmidt said. ‘The human motor system is not perfect, and it doesn’t always do what it is told.”

If you were lucky, your reflexes and muscle-memory and driving experience — and sheer chance — saved you and you emerged unscathed from your near-miss. But you could just have easily smashed your foot down on the wrong pedal or jerked the wheel the wrong way. Or hit the radio volume and scared yourself into a dangerous maneuver. Or made a dozen other mistakes. And none of those would have been the fault of the automaker.

Follow me on Twitter at @theticker

By Frank Ahrens  |  March 4, 2010; 1:31 PM ET
Categories:  Congress , Corporations , The Ticker  | Tags: Akio Toyoda, David Cole, Eleanor Holmes Norton, Toyota problems, Yoshimi Inaba, auto engineering, automotive engineering, engineering testing, testing toyota software, toyota, toyota congressional hearings  
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Nice article. You have a good description of what the complexity of having faults with interconnected electronic systems. Each system can be independently tested, but put them together and there can be bugs introduced due to their interaction. However, you fail to mention that most auto manufacturers have a fail safe for their electronic throttles. I guess Toyota decided it doesn't make mistakes and didn't need one. They also have kept insisting that the electronics aren't the problem.

Posted by: lauther266 | March 4, 2010 2:18 PM | Report abuse

Everything Ahrens says about how engineers establish causes of problems (via what is essentially the scientific method) might be true. However, this editorial seems to miss the bigger point (correctly) being made by Norton and other in Congress. Regardless of whether a bunch of engineers can replicate an event or not, there might nonetheless still be a very real problem, one which remains fully Toyota's responsibility to promptly address. Just because engineers can't replicate reality doesn't mean reality doesn't exist. Precisely because there are 20,000 parts in a modern auto, engineers should know this.

Posted by: joeygsb | March 4, 2010 2:19 PM | Report abuse

toyota has said that the problem is not in the software...BS. replacing gas pedals will not take care of the problem. it "is" in the computers! they know replacing and fixing computers will cost big bucks and lose all customers confidence in their product!! siyonara, toyota.

Posted by: astroman215aolcom | March 4, 2010 2:21 PM | Report abuse

So far as the last part about pushing on the wrong pedal, of course that could happen, but 2000+ reports indicate a trend that points to other things. So far as the software, this is why Star Wars is such a bad idea, until we use it for real we'll never know if all the software will do what it is supposed to. Software in a car driven by millions of people means there are a lot of opportunities for the bug to crop up and for bad reactions. Smart cars are more dangerous than a smart phone.

Posted by: tojo45 | March 4, 2010 2:21 PM | Report abuse


Thank you! ! ! !

As an engineer, I value and appreciate a journalist willing to step up to those people who say, "Well, it doesn't take an engineer to figure that your need to do (fill in the blank)" when that, indeed, yes you DO need an engineer to find the answer because otherwise you're guessing.

Posted by: contrarian4 | March 4, 2010 2:28 PM | Report abuse

What's this? A bit of rationality in a sea of hysteria and jingoism?

A breath of fresh air. Thank you Mr. Ahrens.

Posted by: douglaslbarber | March 4, 2010 2:37 PM | Report abuse

Step on the gas and the cars go, step on the brake and they stop, get them mixed up and you're in trouble.
Audi had the same problem a few years ago.

Posted by: garys_opinion | March 4, 2010 2:38 PM | Report abuse

I've heard these sob stories of people making phone calls to say goodbye, but why didn't they just do one simple thing:


Am I missing something here?

Posted by: cyberfool | March 4, 2010 2:38 PM | Report abuse

I have a question. If it has happened 2000 times, how many times has it NOT happened? Take the number of cars, the number of times each car is driven, multiply them. The divide 2000 by that big big number. That is called the "odds". Saying that something happened 2000 times is fairly meaningless unless you compare it to how often it doesn't happen.

After all, how often do people NOT get hit by a metorite?

Posted by: cyberfool | March 4, 2010 2:41 PM | Report abuse

Best article I've seen in mainstream media on the topic so far, by a mile. The buzz in engineering circles is that it's unlikely to be anything *but* a firmware bug. The problem with politicians (ok, one problem with politicians) is that they think they know everything. In this case, they know precious little and are acting out of ignorance and uninformed intuition. Eleanor Holmes Norton, whom I have great respect for, was simply waaaaay out of her depth, and had it totally wrong. She owes Mr. Toyoda an apology. So how to find the bug? Log all data. Install cell modems in cars to get the data over the air. Record every application of accelerator and brake and correlate with engine data. What if the wires are getting crossed to the computer's sensor inputs, you might ask? Ok, in one of the repeat offender cars, install a low-light camera pointing at the pedals. Record the pictures in real time, with time stamps. There are lots of things that can be done to help find this problem. Is it hard? Yes. If it were easy, anyone could be an engineer - even a politician! But difficulty isn't a reason not to do it!

Posted by: archtop | March 4, 2010 2:43 PM | Report abuse

Automotive software is nowhere nearly as complex as this article represents. It is, in fact very simple. The reason that no can "prove" there is a problem is that there is no trouble code programmed into the CPU to account for the problem. The computer DOES NOT simply say: "There was a problem." Rather, automotive CPUs register and store a code for specific sensors and/or systems when they operate outside of given parameters. There is no sensor for this malfunction and no corresponding code within the CPU. It may be possible to use some existing sensor or system, but Toyo has not yet done this. Given their consistent denial of any electronic problem, it is not surprising that they have not yet done so. As for turning off the key, that is a patently ridiculous suggestion. Once the key is off, there is no power braking and the steering wheel locks. Try that on the freeway!

Posted by: skynet91 | March 4, 2010 2:50 PM | Report abuse

Stating that politicians are too simple-minded to understand anything complex, is a simple statement of the obvious. Add the hubris, arrogance, and petty anger of the average politician to the formula, and you can now understand why politicians and our "government" cannot achieve anything of lasting value. They are the playground bullies seated at the back of the class, who are now able to pretend they are valuable by virtue of holding political office. Of course, they defer to "expert authority" on everything, empowering "experts" with the biggest "attitudes" to further screw-up the Country (from Bernanke and Geither on down). The Obama Administration and Congress need to be sent home with no cookies...

Posted by: wcmillionairre | March 4, 2010 2:54 PM | Report abuse

Failure analysis an investigation is part of my job as an electrical engineer. Sometimes, I can figure out why something happened fairly easily and experience helps in this area.

But other times, there isn't enough information available. For instance, you can figure out what caused the failure but HOW it happened can be nearly impossible because you can not prove which gremlins did it.

The problem with product design is that you can never imagine what humans will do your product. It's a good idea to always remember that a human body can have a total of 7 or 8 orifices.

Posted by: aredant | March 4, 2010 2:58 PM | Report abuse

I'm a software engineer, and I can say without reservation that software is almost universally defective. We don't have the same kinds of engineering standards for software that we do for buildings and bridges, because we don't have centuries of experience behind us. We're still inventing the trade.

archtop is exactly right. This is a firmware bug, and the only way to find it is logging. When it is found, it'll be a lesson to software engineers in what we cannot and should not do, in the same way that the 1284 collapse of the Beauvais cathedral was a lesson to civil engineers.

Posted by: sisina | March 4, 2010 3:04 PM | Report abuse

Please do not use Rep. Eleanor Holmes Norton as an example of anything. Talk about a wetware failure. (end snark)

Random or very rare failures are VERY difficult to troubleshoot. All of the suggested causes are plausible and may have happened. Cruise control hardware/software is where I would look for possible electronic failure. As we all know holding the cruise control lever up to Resume causes acceleration. Moisture in the switch, harness or shorts in wires might instruct the CC to speed up. Fellow Toyota drivers might hit the CC On/Off button. Better than turning off the key and having locked steering.

Posted by: LHO39 | March 4, 2010 3:05 PM | Report abuse

The problem is software in a sense, since there is no rational reason for the system not to have brakes overide the accelerator.
From what I have heard I suspect the problem is in the lack of redundant sensors on the accelerator, combined with less than bullet proof SW. They should have several redundant methods to insure that applying the brakes shut down the acceleration, and several separate methods to insure that accelerator is acutally being pressed.

Posted by: Muddy_Buddy_2000 | March 4, 2010 3:16 PM | Report abuse

This is a very well thought out article from an engineering perspective. To Toyota's credit, at no time have they closed the door to the possibility of electronic/electrical or software glitches being the root cause of the problem. It is understood that at this time there is no evidence supporting the popular idea that it is ETC related. I'm confident that Toyota will fix any problem should a specific component or software code be identified as the culprit.

Posted by: quest2010 | March 4, 2010 3:18 PM | Report abuse

History will show that this entire episode was brought about by public and governmental hysteria. The only problem with these cars is that they are driven by humans. When millions of cars are driven billions of miles, the occasion will come when people find a way to get themselves killed. Pure driver error, not Toyota failure.

Posted by: Dawny_Chambers | March 4, 2010 3:22 PM | Report abuse


Come ON. Consider automotive technology from the 1960s. The only way you could get a runaway situation in a car of that era was a stuck linkage, easily found, easily overridden while driving, easily repaired.

Analog mechanical systems aren't prone to the sort of failure that plagues electronics. Electronics have a short service life so modern engine management systems are GOING to fail, and are too complex to reliably diagnose.

It's perfectly easy to design a machine that will go down the road reliably, and be easily repaired when it breaks. Been done for decades. Pry three of four computers out from under the hood and see how the problem goes away.

Posted by: info53 | March 4, 2010 3:31 PM | Report abuse

The Toyota flap is a classic case of Münchausen syndrome, plus the usual stampede to jump on a litigation bandwagon. Also, it is quite likely that the drivers who have reported cases of unintended acceleration are the same individuals who previously claimed to have been abducted by aliens.

Posted by: donnolo | March 4, 2010 3:32 PM | Report abuse

This excellent article reveals the difficulties in identifying problems in complex systems where such factors as human error, strange boundary conditions and more complicate the problem. Before castigating Toyota exclusively, it is incumbent upon those with the data to compare the problems reported by Toyota owners with the quantity, severity, and frequency of problems that Ford, BMW, Honda, Subaru and all the others face. Is Toyota statistically any different from other manufacturers? Before attacking, it is essential to measure Toyota against the industry as whole. I suspect that it is as good as any manufacturer.

Posted by: migliori | March 4, 2010 3:36 PM | Report abuse

And we're going to rely on people like Eleanor Holmes Norton to understand health care? I wish there was a qualification test to run for political office. I also notice that none of the pols had the guts to ask the crying driver-witnesses a simple question: Why didn't you just shut the engine off or put it in neutral? It's better theater for the pols so show how they are protecting us. It's a shame the media outlets give them the attention. You know, it just encourages them!

Posted by: jsjmmurray | March 4, 2010 3:37 PM | Report abuse

The reason the congressmen were upset was not that Toyota failed to find and fix the glitch but that they only tried to find the engineering symptom of the problem rather than to fix the real problem. The real problem is not that there is a stuck accelerator, but that it causes a crash. Obvious fixes to THAT problem are to have much stronger brakes that can stop with a full throttle engine, to have a cut off to the accelerator when the brake is applied (or pumped) or to have an easy and obvious way to put the car in neutral or turn off the engine (even if in a rental car), or some combination.

Posted by: fineman | March 4, 2010 3:41 PM | Report abuse

Let me add another issue that I don't see discussed here, along the lines of human error, though I know it will be rather unpopular: age.

The Toyota Camry, and especially its blingy twin, the Lexus ES, have a relatively high average age of owner. The average Lexus buyer is 51. The average age of a Camry buyer is 52, which is a whopping ten years older than an Accord or Altima buyer. These cars, among other Toyota models, are the chief culprits in UA. Coincidence?

Yes, I know that older drivers are not necessarily statistically more prone to accidents, but obviously, motor skills, reaction time, and cognitive abilities often decline in our later years. I'm not trying to hate on older folks here, but if we are going to point a finger under the hood, where no flaw has been found, we should look at factors which we know can drive a mechanism of failure.

Furthermore, it hasn't been discssed that we also have to consider whether there might be mulitple causes of which a glitch, if any, might only be the proximate one.

In failures of well-tested systems, such as commercial aircraft, the result is rarely a single one and rarely catalyzed by an obvious or well-understood factor.

If we learned anything from the Audi debacle, it is that our lay understanding of complex machines, however common they are, can lead us far astray from the true story. Even if you don't accept that that lack of a technical verdict against the Audi 5000 meant there was no flaw, you have to conclude that our ability to understand these things well enough to cast blame is very limited.

Posted by: wharwood | March 4, 2010 3:44 PM | Report abuse

I've heard these sob stories of people making phone calls to say goodbye, but why didn't they just do one simple thing:


Am I missing something here?

Posted by: cyberfool | March 4, 2010 2:38 PM

Unless you drive a car from the early '70s, the ignition and shifter are electro-mechanically linked so that the key can't be turned unless the shift is in "P" or "N". In a panic situation, shifting out of "D" may not be the first thing to pop into your mind! I have drilled it into all of my kids, though!

Posted by: Ramblwrk68 | March 4, 2010 3:49 PM | Report abuse

Thanks for the informative article. I have already read too many articles and too many comments by readers of these articles with no engineering knowledge and don't know what they are talking about.

Posted by: carbon916 | March 4, 2010 3:52 PM | Report abuse

Excellent piece, except for the last section blaming drivers for the problem. Ahrens' comments overlook the simple fact that the incidence of this type of driver error should be no higher for Toyota vehicles than for any others.

Also, the suggestion by cyberfool to just turn the key off is bad advice. Turning off the engine causes loss of power steering and power braking, making the vehicle much more difficult to control. Shifting into neutral is the correct move.

Posted by: quadpharma | March 4, 2010 3:54 PM | Report abuse

These two comments are examples of people with little knowledge making assumptions about the problem.
"I've heard these sob stories of people making phone calls to say goodbye, but why didn't they just do one simple thing:


Am I missing something here?"
"Once the key is off, there is no power braking and the steering wheel locks."
Many of the cars do not have a key, they have a push button start/stop. In order to stop the engine while the car is running, you have to hold the button in for 3-5 seconds or you have to hit it 3 times in rapid succession. How many people read the manual and remember that in an emergency.

When the engine is off, you may lose power steering (some have electric power which keeps working) and power brakes (after you use the brakes and deplete the vacuum) but you do not lock the steering wheel. With automatic transmission, you have to be in park and turn the key an additional notch. With a manual transmission, in theory you could lock the steering if you turn the key all the way to the second notch but typically you have to do an extra press of the key or push a button to do it.

Bottom line, both of those statements above show that people do not understand how these things work. One of the side effects of treating our cars like appliances.

Best advice I can give is read the owners manual and think about what you would do in an emergency before hand. Even practice (holding that button in for 3 seconds seems like an eternity when you're driving 60 mph).

Back to the issue, as others have said, no software is perfect. Real-time software/firmware bugs are particularly hard to find. It could very well be that and it could be virtually impossible to find. Hence, having things like override controls is important (e.g., if brake and gas are both on, kill engine). Other manufacturers do that (GM, BMW, etc.). Why didn't Toyota?

Posted by: rrosen3 | March 4, 2010 3:57 PM | Report abuse

Pursuant to my premise above, that modern cars are overdesigned, let me just add this: my "newest" car, a 1990 Chrysler, is the only car I own with electronic engine management. Because of that, it has the most problems.

If someone uses a Toyota keyless remote near my car, it won't start. Until you beep the remote button again a few times.

Something in the RF from the remote is jamming up the data bus in the Chrysler, apparently.

That's the most ridiculous thing I ever heard of. Until now, of course.

Posted by: info53 | March 4, 2010 3:57 PM | Report abuse

This is way we should never put a limit or caps on law suits.Toyota can't even tell us why the cars they are making are having the problems that they are but Toyta are still selling them every day.Mean while,our government sit there does nothing while innocent childern die as a result of a sick minded individual that want to make a profit.IN STEP TRIAL LAWYERS.In america they have set the standard for consumer products.When trial lawyers finish with Toyota,Toyota will pay it's victims,It will recall all those junk cars and junk them,there will be plenty of evidence to be used in criminal prosecution and Judges that have heard and viewed hours of testimony.MAKE THEM PAY,PUT THEM IN JAIL AND MAKE THEIR PRODUCT SAFE.

Posted by: apez54 | March 4, 2010 3:58 PM | Report abuse

The Prius doesn't have a key. It has a start button, which has to be held down for a period of time, in order to turn off the engine.

Yes, you press "start" to stop. Very intuitive.

At least one software bug (a repeatable one) causing unintended acceleration has bee found by Steve Wozniak.

Posted by: wiredog | March 4, 2010 3:59 PM | Report abuse

Thanks for a good article. Finally something from the Wapo that doesn't border on hysterical Chicken Little reporting.

What was missing from all the testimony on the Hill was that many of these crashes that involved injury and death could have been prevented by the driver just pressing on the brakes.

Toyota does not produce a car that can out power it's own brakes. If a Camry enters a full throttle stuck acceleration test at 60 MPH, it takes the brakes only 8 more feet to stop it than if the accelerator were not stuck.

Posted by: 8-man | March 4, 2010 4:00 PM | Report abuse

Ahrens sounds like an apologist for Toyota. My family owns two Priuses, a 2003 and a 2005. My wife, my son, and I all have experienced sudden acceleration. We experienced it ever since both cars were new, so it is not caused by wear and tear. Sometimes it happens with the foot on the brakes, sometimes it happens with the foot on the accelerator, and I've even experienced it with my foot on neither. So far, whenever it happens, stepping hard on the brakes allows us to control the cars. The acceleration, so far, ended within three seconds and usually in less than two seconds. If it doesn't end, we plan to turn off the car (knowing that this will make steering more difficult). It happens, in both cars, maybe every other week. Having seen it as often as I have, I know it is NOT caused by the brakes; it is not caused by the accelerator pedal or the carpet; and it is not caused by driver error. (I suspect that it is triggered by turning the steering wheel.) To say that it is driver error is an insult. For Toyota to say it is not electronics (a software bug is part of the "electronics") is an insult to our intelligence.

Posted by: words1inger | March 4, 2010 4:04 PM | Report abuse

Hey - here's a good reason to own a car with a stick shift. The hydraulic clutch is very reliable!! Put your foot on that and it no longer matters how fast the engine is turning.

Posted by: vdev | March 4, 2010 4:05 PM | Report abuse

Thanks for the article discussing the challenge Toyota faces. Detection in complex systems frequently NOT easy, simply or cheap. It will be interesting to see just how long it takes Toyota, NHTSA, or some other institution to figure it out. Looks like a great case study for future engineers and technology companies. I'm glad I drive an old car that I ca fix myself. As for politicians - just one more example to have fear for whatever they become involved in.

Posted by: notamullethead | March 4, 2010 4:06 PM | Report abuse

I'm not one to tell you that I told you so, so I won't. At least, not yet.

Posted by: jralger | March 4, 2010 4:06 PM | Report abuse

"When the driver says they have their foot on the brake, they are just plain wrong,’ Schmidt said. ‘The human motor system is not perfect, and it doesn’t always do what it is told.”

This may be true in split-second accidents, but do you really think someone could face acceleration for long distances, not being able to stop, acceleration increasing to as much as 100 mph without coming to the realization that the pedal they are pressing (accelerator) isn't working, try the other one (brake)? As in the case with the officer and his family in CA (and other documented cases), I really don't think this possibility applies.

Posted by: n8dc | March 4, 2010 4:07 PM | Report abuse

Heh, heh, I think I suggested the same a few weeks back, Norton and Ray LaHood were talking cars, Mr LaHood has a sociology degree.

The bottom line is that neither should opening their mouth without an expert. They just don't know anything. Period. Again, we will see lawsuits won based on nothing.

It is possible to blame the people, this, in fact, could be a hysteria like the Salem witch trial, and not that people lie to cya but our logic trees might work from the assumption that we are great drivers hence the fault must lie somewhere else.

I predict NHSTA will never find a problem with the system (but lawsuits will be won)

Posted by: jhtlag1 | March 4, 2010 4:12 PM | Report abuse

Nice article.

Of course, at least some of these acceleration cases have to do with problems somewhere in the vehicle. If people have long enough to call 911 while the car speeds along, then they aren't accidentally pushing the wrong pedal. But in most split-second accelerations, yes, driver error is almost certainly to blame the vast majority of the time.

Complaints about sudden acceleration did not originate with Toyota. These complaints have cropped up again and again for decades, and normally drivers have been to blame. Car companies have redesigned their brakes and gas pedals in response, making it harder to miss the brake while making the gas pedal a smaller target, but there is really no way to avoid every accident. Drivers make mistakes. Car companies can design vehicles to minimize driver error, but nobody can eliminate it.

What confuses me is why Toyota issued a "fix" for the problem when they didn't yet actually know what the problem is. They still don't know, and they haven't been able to recreate the problem in testing. The fix cannot be a fix if the problem isn't diagnosed first, which suggests to me that it was little more than a PR move, but a strange one given that it is bound to backfire when, if there is a flaw in the cars, the acceleration problem persists.

Posted by: blert | March 4, 2010 4:22 PM | Report abuse

Thanks for this article. I'm a Toyota owner and I'm not letting them off the hook by any means but as an engineer I've been frustrated with people thinking that it should be an easy thing for Toyota to just go and fix and find the problem.

Posted by: winterrain107 | March 4, 2010 4:25 PM | Report abuse

"Toyota must search its data and look for patterns, for similarities among the incidents"

No doubt both the media and politicians have unreasonable attitudes towards risk. Whenever some problem happens, the media always makes copy out of somebody who warned about the risk. Of course, we always live with risk and there are always those who worry excessively about it. Sometimes they turn out to be right.
No doubt different kinds of engineering have different reliability issues. My experience is with software. The reality of software is that it always has undiscovered problems. Another reality is that any organization producing software has a very hard time understanding the software that they produce. Any control system implemented in computer software needs some kind of manual override in case the control system stops working because of a sofware failure. That same requirement probably applies to any electronic control system.
The first time there was any kind of issue with loss of control over Toyota vehicles, Toyota should have been able to describe the failsafe they built in to their cars to bring them to a safe stop in the event of a control system failure. The fact that we still have no clear description of an absolutely dependable procedure for stopping the cars in the event of a control system failure, is pretty strong evidence that it was not designed in. That failure is a large failure for Toyta engineering that has nothing to do with the difficulties of analyzing problems. I have owned three Toyota cars and been very happy with them. But I certainly would not buy any electronically controlled Toyota car until they design in an absolutely reliable procedure to override the control system if it should fail to perform as expected.

Posted by: dnjake | March 4, 2010 4:38 PM | Report abuse

Dumb question. I have a 2004 Toyota Camery with none of those problems. Why can't they go back to what they were doing right then? The floor mat stays in place because there are two hooks on the floor for it.

Posted by: ashcat | March 4, 2010 5:04 PM | Report abuse

A truly excellent article looking into the difficulty of the problem. It is noted that the author is a degreed engineer if not a practicing one. As an engineer with over fory years of experience in the design, building, program management, and operation of weapon systems I would point out that there is another methodoloy that can be pursued. The Failure Mode and Effects Analysis (FMEA) looks at the possible causes of failure. Since only one effect is being considered it would not be quite as expensive as a full FMEA.

I would also note that touching the brake pedal on my Lexus disengages the throttle.

I hope that your article with all its comments is being read not only by Toyota, but by all the legislators involved. Perhaps the Washington Post should send it to them.

Posted by: hlleon5 | March 4, 2010 5:07 PM | Report abuse

The engineers have gone too far if the driver cannot override a computer with respect to the gas pedal and brakes.

Still missing my 1949 Chevy fastback! The only innovations it needed was fuel injection and seat belts.

Posted by: Bartolo1 | March 4, 2010 6:44 PM | Report abuse

Current events are consistent with Toyota's track record of stonewalling customers. 1zz engine failures, probably attributable to oil sludge, are one of many examples. The "trick" was to exclude these engines from recall.

A short while ago, the AP reported that Toyota has been secretive with "black box" data, even settling cases out of court to avoid releasing the information. The list of reasons not to trust Toyota gets longer every day.

Posted by: ParrisBoyd | March 4, 2010 10:16 PM | Report abuse

Great article with a needed focus on the engineering efforts that must be completed before the problems can be solved. I was amazed at the large number of comments that were posted, many very thoughtful, some with a level of understanding that ranked with that attributed to the politicians.

Posted by: rrgeek | March 4, 2010 11:25 PM | Report abuse

thank you for this great article ,it makes me understand how complex it is for toyota to figure out the problem.

Posted by: jeanbarre | March 5, 2010 2:02 AM | Report abuse

The 'engineering method' is seriously flawed and an insult to consumers.

I am so tired of car mechanics using the excuse "we can not duplicate the problem" as an excuse for ignoring it. Several times over 20 years I have taken a car in for various problems and explained exactly what the symptom was - and often how to fix it, but then I pick the car up later to be insulted with, "We could not duplicate blah blah blah...".

OK, Mr brilliant mechanic, let's say you DID hear the right-rear speaker rattle over bumps as I had carefully described - what would you do, dummy? Maybe TIGHTEN the screws? Install a new speaker? Yeah try some of those things - use some deductive reasoning - rather than simply do NOTHING and waste my time! As if I have nothing better to do with my time than concoct stories and then inconvenience myself by taking a car in for unneeded service. Gees.

The silly notion that the only way you can attempt repair is to duplicate the problem (the 'engineering method') is seriously flawed - and the Toyota boondoggle is solid proof.

Posted by: Oblio_A | March 5, 2010 9:01 AM | Report abuse

I have some observations regarding at least the Prius, of which I own a 2005 model.

First, it is not labeled a 'Start' button, it says 'Power'. In addition to turning off the car, you can disengage the transmission using either the gear shifter to 'N' or by pressing the 'Park' button, which I discovered by accident recently.

Second, one writer mentioned that both his 2003 and 2005 Prius experience sudden acceleration regularly. I wonder if he is confusing engine revving with acceleration. On many hybrids, including the Prius, the engine is not directly connected to the drive shaft and engine speed is a function of the power demand, not speed. Is the car really speeding up, or did the car just decide to charge the battery?

I also am curious if one of the problems is related the cruise control. If there is a wiring problem in the steering wheel, activating the Accel function, this could explain the acceleration, but would release as soon as the brake is touched.

Posted by: DGSteig | March 5, 2010 10:34 AM | Report abuse

Thank you rrosen3 for providing valid info about how today's car actually function. I've effortlessly put many cars into neutral while underway, so this is not an impossible operation. And yes, turning off the ignition will neither lock the steering wheel, nor prevent you from having braking capabilities (although it'll be more difficult), nor prevent you from shifting into neutral.

The March 2010 issue of Car & Driver performed a test with a Camry & Infinity G37 where they braked from 70 mph & 100 mph with the throttles closed & wide open. There was very little difference in the braking distances from 70 mph in either car, but there was a significant difference from 100 mph with the Camry (90 feet more vs 6 feet for the G37). What caused this difference...Infinity, like a number of other manufacturers, programs it's throttle control to close the throttle when the brake pedal is depressed. Thanks to the current investigation, Toyota is adding this feature to it's cars as we speak.

It's more important than ever for owners to read their manuals as cars have become more complicated. For example, to stop cars with push-button starters, it may be necessary to depress the button for several seconds (Camry 3.3 sec vs 2.5 sec for the Infinity) or depress it rapidly several times (3 for the G37).

When Audi had their problems 15-20 years ago, it was concluded there was a human component to the "failure". Audi pedals were offset to the left when compared to domestics, so owners were actually depressing the accelerator when they thought they were depressing the brake.

Does this mean software glitches aren't involved? Not necessarily. However, there are actions owners can take if they happen to experience this problem. Taking the car out of gear & braking are the most effective. Knowing how to turn off the ignition without locking the steering column & the impact this action has on steering/braking should be tested, so the first time you attempt this is not when the car takes off, but in a more controlled environment like a vacant parking lot.

Yes, Toyota can stand to make several changes to its vehicles, but I believe the human factor can't be ignored. Most braking systems on modern cars will overpower the motors so we're still able to stop our vehicles, while maintaining control.

Good article.

Posted by: skipster56 | March 5, 2010 10:42 AM | Report abuse

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